The present invention relates to a switching regulator of the type including a direct input voltage source, an electronic switch connected between the voltage source and an output, a pulse width modulator connected for controlling the electronic switch, a sawtooth signal generator connected for feeding the pulse width modulator a sawtooth signal of constant amplitude, and a proportional signal circuit for feeding the pulse width modulator a signal proportional to current through the electronic switch.
Such a switching regulator is disclosed in German Patent No. 2,920,166. The combined control of the electronic switch, or setting member, by a sawtooth signal and a signal proportional to switch current results in a switching regulator of high stability, particularly with respect to the tendency to oscillate, even in cases where the keying ratio (switch on-to-off ratio) is more than half the duration of the period of the switching frequency.